Disinfectants are among the many compounds currently being studied as alternatives to antibiotic growth promoters in poultry production. The study investigates the influence of peracetic acid (PAA) on hematologic parameters in Cherry Valley strain ducks, administered at different concentrations at two-, four-, and six-week time points to assess toxicity when used as an in-water supplement to improve production parameters. No gross lesions or deaths were observed during the experiment and necropsy. No notable erythrocytic manifestations occurred, but the 50 ppm-treated group showed a significant increase in white blood cell counts at the two-week and six-week time points compared to their respective control groups. Our study demonstrates 10 ppm and 30 ppm as in-water inclusion levels of PAA that show no evidence of hematologic derangements.